Rare genetic changes that may be responsible for the development of schizophrenia have been identified by scientists at the Centre for Addiction and Mental Health (CAMH) in Toronto, Canada.
Many of these same genetic lesions had been previously linked to autism spectrum disorder (ASD). The finding provides more evidence that multiple rare genetic changes may contribute to schizophrenia and other brain disorders.
This discovery also suggests that clinical DNA (genome-wide microarray) testing may be helpful in demystifying schizophrenia, one of the most complex and stigmatized human diseases.
In the novel study, scientists analyzed the DNA of 459 Canadian adults with schizophrenia to identify any rare genetic changes of potential clinical significance.
“We found a significant number of large rare changes in the chromosome structure that we then reported back to the patients and their families,” said Anne Bassett, M.D., director of CAMH’s Clinical Genetics Research Program and Canada Research Chair in Schizophrenia Genetics and Genomic Disorders at the University of Toronto.
“In total, we expect that up to eight percent of schizophrenia may be caused in part by such genetic changes — this translates to roughly one in every 13 people with the illness.” These include several new discoveries for schizophrenia, including lesions on chromosome 2.
The researchers also developed a systematic approach to aid in the discovery and analysis of new, smaller rare genetic changes linked to schizophrenia, which provides dozens of new leads for scientists studying the illness.
“We were able to identify smaller changes in chromosome structure that may play an important role in schizophrenia—and that these often involve more than one gene in a single person with the illness,” added Bassett, who is also a clinician scientist in the Campbell Family Mental Health Research Institute.
“Moving forward, we will be able to study common pathways affected by these different genetic changes and examine how they affect brain development—the more we know about where the illness comes from, the more possibilities there will be for the development of new treatments.”
Several of the genes and pathways identified in this study of schizophrenia have also been linked to ASD. This includes the large rare changes in chromosome structure of potential clinical significance.
“We have seen the success clinical microarray testing has had in making sense of ASD for families, and we think the same could be true for schizophrenia,” added co-author Stephen Scherer, Ph.D., director of TCAG and the University of Toronto’s McLaughlin Centre.
The study is published in the current issue of Human Molecular Genetics.
Source: Human Molecular Genetics